An excavator that had been working normally suddenly started shaking during operation — but only when the excavator's undercarriage was slightly tilted. When working on flat ground, everything appeared perfectly normal. Upon first hearing this report, it was almost unbelievable.

After driving to the site, our LUYU technicians observed that the excavator was operating in a narrow trench, and the issue was exactly as described. When the excavator’s undercarriage was tilted, the machine shook violently; once moved back onto level ground, the shaking stopped immediately. This pattern repeated consistently, yet all external components appeared normal.

At the worksite, our engineers began troubleshooting from the wiring harness, since earlier analysis suggested that all components were functioning properly — raising the possibility of a loose or faulty electrical connection. Inspection around the hydraulic pump soon revealed the true cause: the metal clip used to secure the harness and sensor wires at the bottom of the hydraulic pump had worn through the insulation of a wire, exposing the copper strands.

When the excavator's undercarriage tilted, the sharp edge of the clip made contact with the exposed copper, creating a short circuit. The vibration of the hydraulic pump caused intermittent contact, resulting in irregular motion and shaking. When the excavator was level, however, the contact point was separated, and the machine operated smoothly.